HIV blocks and hardens arteries

posted: 07/01/2010

Even young men with HIV are more likely to have hardening of the arteries than similar men who don’t have HIV. The researchers also found that arterial disease was so severe in 7% of men with HIV that it was blocking blood flow. The longer people have lived with HIV the more likely coronary arteries have hardened and narrowed.

Anti-HIV treatment significantly extends the life expectancy of people with HIV. HIV-related illnesses are now uncommon among people taking treatment but there’s a lot of evidence for a much greater risk of various diseases of ageing, including cardiovascular disease. Hardening and narrowing of the arteries are types of cardiovascular disease.

Spot it early and act

Getting cardiovascular disease spotted early means people can get the right treatment and lifestyle advice to help make a difference to health and cut the risk of heart attacks and strokes later.

A USA study published in AIDS used coronary computed tomography (CT) angiography (a scan of the coronary arteries) to look for and carefully measure any hardening of the coronary arteries before any symptoms showed up. It shows how much plaque (fatty and other deposits) line the arteries and how narrow the arteries have become.

It is HIV that raises the risks

The investigators compared 78 HIV-positive men and 32 HIV-negative men to see if having HIV raised the risk of hardening of the arteries. It did. There was a significant difference. 59% of those with HIV had arteriosclerosis compared to 34% of HIV-negative men and this remained true even after taking out of the equation the traditional risk factors for cardiovascular disease.

They found that the men with HIV had significantly more and thicker arterial plaques (a build-up of deposits lining and narrowing the arteries).

Seriously narrowed arteries found in 7% of HIV+ men

They had more arterial calcium scores, and 7% had seriously narrowed arteries - coronary stenosis – where the arteries were 70% narrower.

None of the HIV-positive men had shown any symptoms of hardened arteries or had any history of heart or kidney disease before they were picked for this scanning trial. On average, they had HIV infection for 14 years; 95% were on anti-HIV treatments, with good CD4 counts (median 523 cells/mm3), and 81% had an undetectable viral load. There were no significant differences between the positive and negative men in the traditional risk factors for cardiovascular disease: the men’s ages, family history of heart disease, blood pressure, cholesterol and Framingham risk scores (the ten year risk of heart disease) were all comparable.

Narrowed arteries linked to how long you’ve had HIV
After taking account of the HIV positive men’s ages and 10 year heart attack risk, the duration of HIV infection remained significantly associated with both the number of plaques and plaque volume.

This is not affected either by treatment with a protease inhibitors, levels of lipids, or CD4 cell count, viral load, or how long you’ve been on HIV treatment.

“The prevalence of coronary artery disease in HIV-infected patients was significantly greater than that seen in…HIV-sero-negative men with similar demographics, Framingham risk scores, and traditional risk factors”, note the investigators.

Even young men can be severely affected
They add, “surprisingly and of important clinical relevance, even among asymptomatic young HIV-infected men, 6.5% had evidence of severe coronary arterial disease…in contrast, [only] one of the controls had severe obstructive coronary arterial disease.”

This study looks likely to raise more worries and questions about why people with HIV have more risk of heart disease. The investigators comment, “our data…support the hypothesis that there is a relationship between HIV infection and coronary artery atherosclerosis independent of traditional risk factors as [these] were generally similar between the two groups.”

Duration of HIV infection had a “significant and robust” relationship with hardening of the coronary artery.

Act early to reduce the risks from other causes
“Our data highlight the need to address cardiac risk reduction early on in the course of HIV disease”, conclude the researchers.
This means not smoking, keeping to a healthy weight, 5 fruit and vegetables a day, regular exercise to get the heart pumping, cut back on alcohol, and the like.

Image credit: US National Heart, Lung, and Blood Institute

Source

Reference
Lo J et al. Increased prevalence of subclinical coronary atherosclerosis detected by coronary computed tomography angiography in HIV-infected men. AIDS (online edition), 2009.

Drinking Worsens HIV+ Cardiovascular Risks

posted: 23/12/2009

Heavy drinking increases the risk of cardiovascular disease for men with HIV, a USA study shows. “Hazardous drinking and alcohol abuse or dependence were significantly associated with an increased prevalence of cardiovascular disease as compared with infrequent or moderate drinkers”, they comment.
 

Even 'light-weight' drinking harms more with HIV

What they mean by 'hazardous drinking' may seem pretty light-weight to men on the gay scene in England. They counted anything over 14 alcoholic drinks in one week as hazardous, and six drinks in a single session, more than once a month, as binge-drinking. At Christmas and New Year many men will be drinking well over these.
 

They emphasise that the study shows the risks of heart and other circulation disease harm is there for men with HIV, even after they took account of the usual risks.

We already know drinking is linked to several health problems in people with HIV. These include

• poor adherence to HIV treatments
• liver disease
• worsening HIV disease, as well as a
• bigger risk of cardiovascular disease.

Among HIV negative people, heavy drinking, binge drinking and alcohol dependency, are well known to cause more heart disease and strokes. Is this the same or worse for people with HIV, was the question this study investigated.

So the US investigators studied 4743 HIV positive and negative men veterans from the USA armed forces. Just over half the men (2422, 51%) were HIV-positive. Both HIV-positive and HIV-negative men were likely to be hazardous drinkers, or to binge drink, or be dependant on alcohol - alcoholics.

HIV negative more likely to have some drinking risks

The HIV negative men were statistically more likely to have several traditional risk factors for cardiovascular disease than HIV positive men. These risks include

• having high cholesterol,
• diabetes,
• high blood pressure and
• being overweight.

HIV positive men have more of these usual drinking risks

HIV positive men were statistically more likely to

• smoke,
• have hepatitis C, and
• have liver disease.

So the study shows HIV-positive, but not HIV-negative men, who are hazardous drinkers or alcohol dependent have a higher risk of cardiovascular disease.

Similar drinking risks shared by positive and negative men

For both HIV-positive and HIV-negative men, these traditional risk factors 

• being older,
• higher cholesterol,
• high blood pressure, and
• smoking

were also significantly associated with more cardiovascular disease.

Affect of HIV on drinking men

They then looked more closely at how HIV itself affects the risks for men with HIV, by taking out of the equation the traditional risk factors for cardiovascular disease.

HIV and drinking – more heart failure, heart disease, cardiovascular disease, strokes
 

They found that hazardous drinking for men with HIV was significantly linked with heart failure; that alcohol dependency was linked to heart disease, and that past alcohol consumption (defined as one or more drink, ever), increased the risk of stroke. Binge drinking increases the risk of cardiovascular disease for those with HIV. [The source quotes how strong these statistical significances are].

“Among HIV-infected veterans, there was a significant increase in the prevalence of cardiovascular disease for hazardous drinking and alcohol abuse”, write the investigators. They suggest that this could partly be explained by the increases in lipids associated with heavy drinking. However, they also note that previous research among this group of US veterans “also demonstrated a temporal and dose-response relationship between alcohol consumption and medication adherence.”

“The effect of alcohol may be more pronounced among those infected with HIV”, conclude the investigators.

How does your own drinking measure up?

One of our earlier articles includes useful weblinks to drink calculators to help you check how much you are drinking and it also tells you where you can get help to cut your drinking down.

Drinking is a common way for men with HIV to manage stress and to socialise, but there is quite a price to pay down the line. As men with HIV live longer because of better HIV treatments, it is more likely men with HIV will die earlier than necessary of alcohol-related cardiovascular disease, [heart attacks, heart failure, strokes, blocked arteries], than of HIV.

Men with HIV who tick these risk boxes, as well as drinking, worsen their life prospects

• smoker
• overweight
• older
• have higher cholesterol
• high blood pressure
• have hepatitis C
• have liver disease
• diabetic.

The more you tick, the higher the risk of harming health and life.

British Heart Foundation page on cardiovasular disease and how to cut your risks

Source

Reference Freiberg and others. The association between alcohol consumption and prevalent cardiovascular diseases among HIV-infected and HIV-uninfected men. J Acquir Immune Defic Syndr 2009.
 

Abacavir - Check for Heart Attack Risks

posted: 06/10/2008

Abacavir: risk of heart attacks compared to tenofovir

Two studies into abacavir, probably caused the most controversial discussions at the AIDS Conference in Mexico.

Abacavir is widely prescribed and recommended as a first-line combination here.

These studies asked:
i) Does abacavir increase risk of heart attack and other cardiovascular problems?
ii) Is abacavir less effective in people who start treatment with a viral load over 100,000 copies/mL, especially when compared to tenofovir?

Both questions were highlighted by independent researchers and GSK, who make and market abacavir have tried to downplay the studies' findings.

Abacavir and heart disease: SMART study supports links found by D:A:D study

In February 2008 at the Retrovirus conference (CROI), the D:A:D researchers reported finding that current or recent abacavir use approximately doubled the risk of having a heart attack compared to other nukes. This was most pronounced in real terms in people who already had high risk of heart disease.

Even though D:A:D was the largest study ever designed to look at heart disease and HIV treatment (over 33,000 people were followed for over seven years), many people wanted confirmation of these results in other studies before they would believe them.

In Mexico, we heard that the large randomised SMART study found similar results (seeing 2 to 4-fold increases in risk) when they looked at abacavir use by patients in their database. This risk was increased however heart disease was defined (ie strictly by having a heart attack, or more broadly including other aspects of heart disease).

They found the risk was most significant in people with high cardiovascular risk (those with 5 or more other risk factors) and that this was seen whether abacavir was compared to all other nukes, or just to tenofovir. They also reported that baseline inflammatory markers (IL-6 and hsCRP were higher in people on abacavir and that this could explain the higher risk, although the design of these studies can only report the association and not show that abacavir caused this. See also the HEAT study below).

Whenever a safety signal is found in a licensed drug, the manufacturer has to investigate. Earlier in the conference, GSK had presented the results from their own database of clinical trials, where they couldn’t find a link to heart disease. However, this doesn’t balance the findings from D:A:D and SMART for several reasons.

Firstly, patients in GSK studies were generally younger and healthier and people with higher cardiovascular risk are usually screed out from taking part in new drug studies.
Age increases cardiovascular risk and GSK patients were around 10 years younger. The GSK database was not designed to look for or record cardiovascular disease, and most importantly, it was not powered to be able to see any link to abacavir use – whether or not they saw anything, there were too few events to make this statistically
meaningful.

HIV-positive people need to check their risk of heart disease using online Framingham calculators . If it is high (20% risk of heart attack in the next 10 years), then use an alternative drug to abacavir, and look at other lifestyle changes that could reduce this risk (exercise, diet, stopping smoking etc).

SMART study (THAB0305)

GSK response (WEAB0106)



Is abacavir/3TC (Kivexa) less effective than tenofovir/FTC (Truvada)?

The second abacavir controversy in Mexico related to whether Kivexa is less effective than Truvada at high viral loads.

This was raised by an independent US study called ACTG A5205 that randomised 1800 patients to either abacavir/3TC or tenofovir/FTC. Earlier this year the study was changed after a safety analysis showed a higher rate of treatment failure in almost 800 patients who started treatment with a viral load that was higher than 100.000
copies/mL. Other drugs in the study were either efavirenz or atazanavir/r, but results from use of these drugs are not yet available.

GSK responded to these findings with results from the HEAT study and a combined analysis (called a meta analysis) from six  abacavir studies.

The HEAT study is the first randomised study comparing abacavir/3TC to tenofovir/FTC and an analysis by baseline viral load showed no differences after 2 years in terms of risk of virological failure or tolerability – although it is a smaller study (with under 700 patients, with only around 150 patients in each group with baseline viral load higher
than 100,000 copies/mL).

Interestingly, the HEAT study found that IL-2 and hsCRP inflammatory markers both dropped significantly during the first year of treatment, but that this occurred in both the abacavir and tenofovir groups at a similar rate.
The meta analysis was not able to measure outcomes in exactly the same way as ACTG A5205 and wasn’t comparing abacavir to tenofovir, but reported similar response rates at higher and lower viral load levels.
Nevertheless, both European (EACS) and UK (BHIVA) guidelines have thought these results important enough for tenofovir to be either preferred as a first-line regimen or preferred in patients with higher baseline viral loads.

Both studies were presented at the late-breaker oral presentations on Thursday:
www.aids2008.org/Pag/PSession.aspx
HEAT study: (late breaker poster)

Source: i-Base about abacavir and i-Base Mexico report